The Real Madrid star and Arsenal midfielder are fit to feature in tomorrow's qualifier in Group B against Andorra.
"It's important not to get drawn into saying that if Gareth and Aaron turn up, we're going to qualify," BBC Sport quotes Gunter as saying.
"It's going to take a whole squad of people, not just 11 players. History tells us that you know that it's tough to get the same team on the pitch for every game."
In their qualifying campaign, Wales will face Bosnia-Herzegovina and Cyprus on home turf on October 10 and 13 before going up against Belgium away on November 16.